When Vasudeva saw that Kaṁsa was determined to kill his sister Devakī, he thought to himself very deeply. Considering the imminent danger of death, he thought of another plan to stop Kaṁsa.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
निर्बन्धं तस्य तं ज्ञात्वा विचिन्त्यानकदुन्दुभिः । प्राप्तं कालं प्रतिव्योढुमिदं तत्रान्वपद्यत
nirbandhaṃ tasya taṃ jñātvā vicintyānakadundubhiḥ | prāptaṃ kālaṃ prativyoḍhumidaṃ tatrānvapadyata
SB 10.1.47